Update Rust gif crate

Cargo.toml

@@ -10,7 +10,7 @@ license = "AGPL-3.0+"
 name = "gifski"
 readme = "README.md"
 repository = "https://github.com/ImageOptim/gifski"
-version = "1.2.1"
+version = "1.2.2"
 autobins = false
 edition = "2018"
 
@@ -21,8 +21,8 @@ name = "gifski"
 [dependencies]
 gifsicle = { version = "1.92.1", optional = true }
 clap = "2.33.3"
-gif = "0.10.3"
-gif-dispose = "2.4.1"
+gif = "0.11"
+gif-dispose = "3"
 imagequant = "2.12.5"
 imgref = "1.7.0"
 lodepng = "3.2.1"
@@ -36,6 +36,8 @@ dunce = "1.0.1"
 crossbeam-channel = "0.4.3"
 
 [dependencies.ffmpeg]
+# package = "ffmpeg-next"
+# version = "4.3.6"
 git = "https://github.com/kornelski/rust-ffmpeg"
 optional = true
 default-features = false

src/error.rs

@@ -14,6 +14,9 @@ quick_error! {
         Gifsicle {
             display("gifsicle failure")
         }
+        Gif(err: gif::EncodingError) {
+            display("GIF encoding error: {}", err)
+        }
         NoFrames {
             display("Found no usable frames to encode")
         }
@@ -40,6 +43,15 @@ quick_error! {
 
 pub type CatResult<T, E = Error> = Result<T, E>;
 
+impl From<gif::EncodingError> for Error {
+    fn from(err: gif::EncodingError) -> Self {
+        match err {
+            gif::EncodingError::Io(err) => err.into(),
+            other => Error::Gif(other),
+        }
+    }
+}
+
 impl<T> From<crossbeam_channel::SendError<T>> for Error {
     fn from(_: crossbeam_channel::SendError<T>) -> Self {
         Self::ThreadSend